>North American Chironomus: C. vockerothi

Species 3w. C. vockerothi Rasmussen.

Was placed in the subgenus Camptochironomus.
It has been suggested that this is a hybrid between C. dilutus and another species.

Adult:
Description largely based on that of Rasmaussen, 1984.

Male:
A mostly dark species, with the hypopygium somewhat darker.

Paratype male of C. vockerothi
a. antenna; b. hypopygium; c. Superior volsella (note the length); d. gonostylus.

Wing length 3.1-3.8 mm, wing width abt. 0.96 mm, VR 0.95-1.0; 19-25 setae in squamal fringe.  AR 1.89-2.35.  Fore LR 0.95-1.09.
Head: Frontal tubercles present, length about 250 µm.  Palpal proportions (segs 2-5)(µm): 68 : 188 : 182 : 245; P5/P4 1.35. P5/P3 1.30.  Clypeus with 21-38 setae.
Thorax: Mesonotal tubercle well developed.  Setae: Acrostichal 8-18; Dorsocentral 25-54, uni- to tri-serial; Prealars 7-14, uni- to bi-serial; Scutellars 29-46, uniserial laterally to multiserial medially, about 14-16 in most posterior row.
Legs (micron):

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	BR
PI	1610	1310	1450	820	620	440	260	0.95-1.09	1.14	1.05-1.24
PII	1530	1550	690	470	370	270	200	0.44-0.45	0.99
PIII	1680	1760	940	580	510	310	210	0.53	0.95-0.96

Male terminalia enlarged, suggesting the species mates on the substrate. Gonostyles strongly curved and narrowing evenly, similar to that of C. dilutus; anal point broad with a squared off end; with two setose lobes flanking it. Superior volsella large, darkly pigmented, curved ventrally towards the apex, and lacking setae. Inferior volsella long and narrow, reaching about half way along the gonostyle.

Female:

Coloration, wing length, squamal setation, and thoracic characters stated to be similar to those of the male.
Additional information from paratype 18183:
Wing length abt. 3.50 mm, width abt 0.94 mm., VR 1.00-1.01.  SCf on brachiolum - abt 4.
Antennal proportions (micron): 105 : 80 : 98 : 113 : 185.  AR about 0.47, A5/A1 about 1.76.
Palp proportions (segs. 2-5) (micron): 80 : 180 : 173 : >245 (shrivelled).  37 clypeal setae
Thoracis setae: abt. 12 acrostichals; 19-23 dorsocentrals (including humerals?); 6 prealar; scutellars in 2 approximate rows 24 in anterior, 12 in posterior row (total 36).

Leg proportions of 1 specimen (micron):

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	Ta4/Ti
PI	1080	1120	1080	620	500	360	180	0.96-1.25	0.96	0.32
PII	1300	1260	620	380	300	200	180	0.42-0.49	1.03
PIII	1420	1420	900	540	460	260	180	0.57-0.65	1.00

Genitalia: Dorsomesal lobe of GpVIII somewhat reduced, with inner margin distinctly sclerotized. GcIX small with 1-2 setae. Segment X large and produced into posterolateral lobes, each bearing 22-35 setae. Ventrolateral lobe short, apodemal lobe small and indistinct on most specimens.

Pupa, Larva and Cytology not known

Found: Alberta - Elkwater (49.65°N, -110.28°W) and Hastings Lake.(Type localities)

Adult alone described by Rasmussen (1984).
Distinguished from C. dilutus and C. pallidivittatus by the smaller size and well developed mesonotal tubercle. The males can be distinguished by the long superior volsella; females by the long extended gonopophysis X.

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